Effects of Midstream Collection and the Menstrual Cycle on Urine Particles and Dipstick Urinalysis among Healthy Females

For urinalysis, midstream collection is recommended (1)(2)(3). Health-associated reference limits for leukocyte and erythrocyte counts in female urine are important for detecting hematuria, pyuria, and urinary tract infection (3). To understand the effects of urinary collection and the menstrual cycle on urinalysis, we examined first-stream and midstream urine samples from healthy female students with use of an automated dipstick reader and the fully automated urine cell analyzer, UF-100.Specimens were obtained from 64 healthy female students (age range, 18–20 years) at the College of Medical Technology. All were asymptomatic and had no extant urologic disease. They were instructed to collect only first and midstream urine samples in sterile containers at the same time and not to wipe or spread the labia. The volume of the first urine was measured, and the specimen was analyzed within 2 h. The students provided written, informed consent to participate in the study as well as information about their menstrual cycles. Specimens were classified into four groups according to the number of days after menstruation as follows: menstrual (1–7 days after menstruation; n = 15), follicular (8–15 days after menstruation; n = 21), ovulatory (16–19 days after menstruation; n = 6), and luteal (20–31 days after menstruation; n = 22).Particles in the urine were analyzed by use of a fully automated urine cell analyzer, UF-100 (Sysmex Corporation). We used the manufacturer-defined review …